角钢热连轧过程的温度场有限元分析

采用有限元软件MSC.Superform对角钢热连轧过程进行有限元模拟。介绍了模拟过程中的模型建立、材料参数、边界条件以及载荷的定义,分析了轧制过程中轧件温度场的分布和变化过程,分析结果对制定角钢热连轧过程的温度制度提供了有效参考。     

CSP带钢热连轧机架间水冷传热数值模拟

采用有限差分方法,建立了CSP热轧过程轧件传热及温度场模拟模型,对CSP带钢热连轧过程中机架间冷却过程的传热进行了模拟计算.讨论了机架间水冷对带钢传热和断面温度演变的影响.     

高速棒材热连轧过程温度场数值模拟

通过对高速棒材轧制、水冷和输送等各个环节热传导及边界条件的分析,应用有限差分法建立高速棒材热连轧过程温度场模型,并对整个连轧过程进行了温度模拟计算,获得轧件表面及其内部温度分布规律。结果表明,计算值和实测值有较好的一致性。     

3104铝板带热连轧过程热力耦合分析

轧制过程是一个非常复杂的大变形过程,难以用准确的数学模型来描述.有限元法不但能解决复杂的非线性问题,而且克服了传统的物理模拟和实验研究成本高且效率低的缺点.通过Gleeble-1500热模拟机进行热压缩实验构建3104铝合金的本构方程,并嵌入到铝板带热连轧三维MSC.Marc有限元模型中.有限元分析热连轧过程温度场和轧制力分析结果表明:全流程温度变化主要发生在第1道次;模拟温度与实测温度接近;轧制力误差在5.0%范围内.该模型能够在实际生产中工艺优化起到重要指导作用.     

冻结法凿井冻结温度场的数值反演与模拟

考虑了冻结孔的实际偏斜状况，提出了基于平面有限元模型的冻结温度场数值反演及模拟方法．介绍了模型的基本特征、计算参数及数值反演、模拟的基本步骤．由于能够模拟冻结孔的实际分布状况及冻结管外表面的温度下降过程，并且以土性参数的反演为前提，因而该模型能够以较高的精度模拟冻结温度场的发展过程．通过某冻结温度场的数值模拟实例验证了该方法的可行性，并对影响数值模拟结果的主要因素进行了分析．     

基于机理与数据驱动的热连轧板凸度组合预测

针对传统热连轧出口板凸度预测方法存在的模型精度低、解释性差等缺陷,提出了一种将机理与数据驱动相结合的热连轧板凸度组合预测模型。通过热连轧板凸度机理预测模型得到热连轧板凸度基准值,将该基准值与实际值之间的偏差量作为机器学习模型的预测变量,再将偏差量预测值与基准值进行求和得出组合预测模型的板凸度预测值,并将该组合预测策略应用至多个神经网络进行方法验证。研究结果表明,提出的热连轧板凸度组合预测模型相较于传统预测模型具有更好的预测性能,其中有97%以上预测数据的绝对误差小于0.02 mm,82%以上预测数据的绝对误差小于0.01 mm,同时该组合预测方法具有较好的可行性与普适性,所提出的模型能够实现机理模型与数据驱动模型的优势互补,使得模型更加符合实际物理意义,该组合模型既缓解了神经网络预测结果由于过程黑箱导致解释性差、可信度低的问题,又弥补了机理模型预测结果偏离生产工况、无法实时修正的缺陷,对热连轧板带钢的板形控制以及热连轧产品质量的改善具有重要意义。     

金属基复合材料凝固过程计算机模拟（Ⅰ）

基于合金凝固过程中的能量守恒定律,建立了纤维增强金属基复合材料凝固过程中温度场的数值模型,研究和讨论了相应的算法,使模型的计算成为可能．     

GMAW 焊接熔滴热焓量分布模型

根据熔滴的过渡过程及其与熔池的相互作用,提出了ＧＭＡＷ（熔化剂气体保护电弧焊）熔滴热焓量在熔池中的分布模型．应用数值模拟技术研究了焊接规范、热焓量分布、焊件温度场的相互影响．焊接工艺实验结果表明,给出的熔滴热焓量分布模型更符合实际,明显提高了温度场的计算精度．     

板带热连轧轧制变形规程的模糊多目标优化设计

研究了目前板带热连轧轧制变形规程设计方法及在该领域中的应用状况，分析并建立了以能耗最低、负荷分配最均衡及板形质量最优的多目标优化模型，并运用模糊学的理论和方法对板带热连轧轧制变形规程多目标优化问题进行了求解．最后以某六机架热连轧机为例，对常规轧制，各单目标优化轧制以及模糊多目标优化轧制的轧制变形规程进行了分析比较，结果表明了该方法的有效性．     

解析刚度理论在板形控制中的应用

热连轧的板带材是冷轧的主要原料,来料板形波动太大不利于对冷轧进行板形控制。针时这一问题,结合国内某热连轧厂的实际情况,建立了板形调控模型。该模型以解析刚度理论为理论基础．通过调整机械板凸度来控制板形。现场试验数据表明,该模型达到了板形的调控目标,可以使产品的出口板形稳定在一个较小的范围内。     

Q235小H型钢轧制过程温度场有限元分析

小H型钢成品的组织性能与轧制过程的温度紧密相关,特别是终轧的温度.结合现场测量结果,应用有限元分析软件对轧制过程的温度场进行模拟,并通过对Q235小H型钢轧制过程各轧制阶段温度的实际测量,与有限元分析结果进行比较,两者误差较小,验证了有限元分析结果的正确性,得到了各阶段H型钢断面温度分布特点以及内外温差值.分析结果对制定加热温度、轧制过程冷却参数、轧制工艺参数和进行轧后控冷等提供了有效参考     

热连轧工艺对GH4648合金棒材组织与性能的影响

研究了连轧生产线生产的GH4648合金热轧棒材的组织与性能.采用热连轧过程的自动化控制系统调整棒材的轧制速度、保持稳定的终轧温度,从而获得晶粒组织均匀、α-Cr相形态与分布合理的热轧棒材.与传统的横列式轧机相比,工艺更稳定、可控,热轧棒材的组织稳定、性能提高.     

3-D thermo-mechanical coupled FEM simulation of continuous hot rolling process of 60SiMnA spring steel bars and rods

The 3-D thermo-mechanical coupled elasto-plastic finite element method (FEM) was used for the simulation of the twopass continuous hot rolling process of 60SiMnA spring steel bars and rods using MARC/AutoForge3.1 software. The simulated resuits visualize the metal flow and the dynamic evolutions of the strain, stress and temperature during the continuous hot rolling, especially inside the work-piece. It is shown that the non-uniform distributions of the strain, stress and temperature on the longitudinal and transverse sections are a distinct characteristic of the continuous hot rolling, which can be used as basic data for improving the tool design, predicting and controlling the micro-structural evolution of a bar and rod.     

Work roll thermal contour prediction model of nonoriented electrical steel sheets in hot strip mills

The demands for profile and flatness of nonoriented electrical steels are becoming more and more severe. The temperature field and thermal contour of work rolls are the key factors that affect the profile and flatness control in the finishing trains of the hot rolling. A theoretic mathematical model was built by a two-dimensional finite difference to calculate the temperature field and thermal contour at any time within the entire rolling campaign in the hot rolling process. To improve the calculating speed and precision, some special solutions were introduced, including the development of this model, the simplification of boundary conditions, the computation of heat transfer coefficient, and the narrower mesh along the edge of the strip. The effects of rolling pace and work roll shifting on the temperature field and thermal contour of work rolls in the hot rolling process were demonstrated. The calculated results of the prediction model are in good agreement with the measured ones and can be applied to guiding profile and flatness control of nonoriented electrical steel sheets in hot strip mills.     

Static and dynamic finite element analysis of 304 stainless steel rod and wire hot continuous rolling process

Three-dimensional finite element models were developed to analyze 304 stainless steel rod and wire hot continuous rolling process with the help of MSC.Marc software. The entire 30-pass deformation process and the actual parameters of production line were taken into account. Static and dynamic procedures were used to study the continuous rolling process with the aid of the thermo-mechanical coupled FEM of elastic-plasticity. The properties of billets, such as deformation, temperature field and rolling force, were mainly discussed. The simulation results of temperature agree well with the measured values. Comparisons of the analysis results obtained using static implicit method and dynamic implicit method were presented. It is shown that static implicit procedure is more accurate than dynamic implicit procedure and is able to simulate the rolling process with a lower speed, such as a roughing mill. Whereas, dynamic analysis shows a higher efficiency than static analysis and is fit for simulating the rolling process with a higher speed, such as a finishing mill.     

Study on Influence of Initial Rolling Temperature for Rolling Process Based on Numerical Simulation

Wire rolling is a typical large deformation process and its principle is very complex,which includes material non- linearity,geometry non-linearity and boundary non-linearity.It is difficult to obtain theory analytical results by trying to roll or physical experiment because they will induce many problems such as high cost,waste time and venture.With the rapid advance- ment of computing technology and numerical method,the finite element method is regarded as the best one,which can account for the large plastic deformation,thermo-mechanical coupling and complex boundary conditions of the rollers and the workpiece inter- actions in the rolling process.Under the different initial rolling temperature,the two-pass hot continuous rolling process of high- speed wire has been simulated accurately for the pre-finishing rolling section.The metal fluxion law and the deformation field have been obtained.Strain,temperature,rolling force and torque also have been simulated and discussed.The results of simulation are useful for practical manufacture and the optimization of process-parameters.     

热轧温度对Zr-4合金力学性能和耐腐蚀性能的影响

热加工工艺对Zr-4合金板材的力学性能及耐腐蚀性能有极其重要的影响,将Zr-4合金板在800℃和960℃两种温度条件下热轧开坯至2.4 mm厚度,经退火后冷轧加工成为1.2 mm和0.6 mm厚的带材,研究了热轧温度对Zr-4合金板材室温力学性能和腐蚀性能的影响.研究表明,800℃热轧后所制备板材的强度低于960℃热轧后的板材,而延伸率大于960℃热轧后的板材;800℃热轧所制备的0.6 mm厚的Zr-4合金板材的腐蚀性能优于960℃热轧所制备的板材.由研究结果可得：Zr-4合金板材在实际生产过程中需合理地控制热加工温度.     

Formation mechanism in alloy steel rolling process using thermo-mechanical coupling method

Based on the theory of elastic-plastic finite element method, the high-speed hot continuous rolling process of a billet is simulated and analyzed in vertical and horizontal passes. The billet is dragged into the passes by contact friction force between the billet and rollers. The rollers and billet are represented by respectively rigid and deformable bodies, and three-dimensional models are developed for the billet and rollers. The distribution of deformation field, effective strain, rolling force and temperature field are accurately calculated for the whole rolling process (including unstable and stable stages). In addition, the rolling pressure on the width symmetry center is compared with that in the in-situ experimental measurements. It is revealed that various heat exchange phenomena among the billet, rollers and surroundings can result in unbalanced temperature distribution on the cross section. Rolling force and strain can change significantly when the billet is moved towards or away from the roller gap, and keep almost invariable in the stable stage. It is expected that the simulation results would be useful for practical manufacture and provide the theoretical foundation for improvement of process planning and optimization of process parameters.